The Knights are living things, as they eat. Also it's been confirmed they are alive. And the souls that fly out out our suits are the ones you saved and the harvester takes them back and presumably eats them.

when the harvester does the soul drain on us, more than one soul comes out....

Why, sure, "we" (the players) are different from other knights. We are immortal, while they can die.

it says in the thread OOO released that we are mechanized that don't run on anything

Source or it didn't happen.

Your theory is so crazy it just might be true!

Don't forget that Impostoclaus brings us presents!

Or a 'tech knight' could simply be a knight using technology.

So let's see what we have here: http://wiki.spiralknights.com/Knights

"The Knights are vertebrates of organic structure, resembling short humanoids with dark skin, glowing eyes and stumpy feet."
We're alive. We have "dark skin, glowing eyes and stumpy feet". Good to know.

"As organic creatures they can suffer from biological imperfection and sickness. They are warm-blooded, have hair, and wear clothes."
The source for "biological imperfection" is the Chroma Tear's description: "A crystallized Chromalisk tear suitable as a lens for focusing weaponry, or for correcting myopia." Sickness is from the Zee Core: "A pungent mass pulled from a slimy assailant. Its aroma is an excellent remedy for insomnia, as well as nighttime sniffling and sneezing." Warm-blooded from Cooling Cell: "A small device used in complex machines to keep them from overheating. Also handy to keep in your pockets on hot summer days." Hair from Vitasuit Plus description, which also gives other hints: "High-tech mail that provides the wearer with myriad medical boons, including bonus health, glossier hair, and fresher breath." Clothing from the Static Clinger, which also gives hints for hair: "A latent strand of energy that floats throughout the Clockworks, frequently catching onto hair and clothing. It's too large to properly distill into Energy, but it's very useful in alchemy."

"Knights can be affected by neurological disruption, are capable of emotions, have various personality traits including those of the anti-social deviation, and in some cases, most notably the Arkus incident, can be driven mad."
The "neurological disruption" refers to the "almost hypnotic trance" in the Dark Ember description: "A mote of burning energy salvaged from Lord Vanaduke's throne room. It slowly smolders with a sinister intensity, creating an almost hypnotic trance when gazed upon for any length of time." The source for emotions is the Enamorock description: "A strange stone that makes you have warm and fuzzy feelings inside just by holding it." The sources for anti-social deviation are both the Mad Bomber Suit - "Some people have axes to grind. Others have points to make. This armor is for those of us with explosive tempers." - and the Ice Queen Mail - "A regal suit of armor resembling the ever-frigid Ice Queen. In addition to providing great defense, it is said to dramatically boost one's ego and create a cold detachment from those around them." And of course, Arkus is a perfect example of a knight's mind being broken.

"They take part in recreational activities, have short noses with a sense of smell and need to, or at least enjoy, eating and drinking; like most vertebrates, they utilize teeth to break down food before digesting it."
Recreational activity: "A viscous compound developed by Biotechs to allow for the study of slime creatures. When mixed with slime and jelly matter, it allows for reshaping without losing its form. Though reserved for scientific purposes, the process is generally regarded as 'super fun'." The sources for the "short noses" and "sense of smell" are the pages Phial of Phear, Royal Core, Vog Cub Coat and Ash Tail cap (oh come on, I'm not posting the descriptions of all those, find 'em yourself). The sources for drinking/eating and mouths are Warp Dust, Rock Salt, Hailstone and Rocky Cores for the mouth (not posting all that!) These are interesting cases as the knights' faces can be fully exposed and have no features but their two eyes.

"Some armors and shields double as cooking apparatus, giving the impression that Knights possibly do not have the biological ability to eliminate harmful bacteria in foreign consumables."
Apparently we can create spaceships capable of interstellar travel, energy weapons and fight alien races on a daily basis but we can't disinfect food.

"Knights have a sense of hearing and a sense of touch, with some armors designed with comfort in mind and others sacrificing comfort for maximum protection."
The Fused Demo Helm tells you about hearing: "An upgraded Demo Helm fused dangerously with the unstable core from a powerful Blast Cube. It produces an unpleasant hum in your ears." Comfortable armors are Azure Guardian Armor and Grey Feather Mantle, and Heavy Plate Mail is all defense, so it seems.

"Knights do need to breathe although it is unknown what they breathe to survive, or if they can breathe the atmosphere of Cradle."
The source for this is the Volcanic Plate Helm's description: "A superior plate helmet forged from volcanic iron. It's difficult to breathe in, but it can resist high temperatures and any number of savage attacks."

"Although Knights are not fused permanently with their armor, they are never seen without it, and rarely without their weapons. Although knights (or possibly their armor) can carry an incredible amount of mass, they are still slowed down substantially when utilizing heavier armor and weaponry."
Apparently the Solid Cobalt Helm's description - "A sturdy Cobalt Helm with upgraded internal systems and external reinforcement." - is the source saying they're not fused with their armor. IMO the fact that they can swap armors is proof enough of that.

Anyway...

TL;DR - they're humanoid, have the five senses, design armor with comfort in mind, can get sick, go inside, have personality deviations, have unseen mouths and noses, have teeth, and can eat. They can breathe and can take off their armor, but they can't disinfect their food.

that is when there kinda put together there a advanced space travelling race so they could be a hybrid of machine and biological mater that would explain how they can come in different sizes and also fit in different armors so well. there biotech could be allowing the more adaptive knights to become better suited for survival then other knights an example of this are Battle Sprites ans its also apparent they might be suffering from lost history as a race.

Or a 'tech knight' could simply be a knight using technology.

Exactly. Or even a more literal translation of that phrase.

A knight's weapons are all stored digitally on some collective server. When a knight wishes to switch weapons, they merely think it, and the server does the work for them, instantaneously popping one of your precious weapons in for another. Access to multiple weapon slots is based on a subscription based monthly fee for making the server work harder to store more weapons tied to your knight.

Or, you know. The simple answer. Hammerspace.

but if there are servers where are the houses holding them or is our armour the servers?

Knights are capable of wielding the shell of an enormous Tortodrone and carry a weapon that's bigger than them without any adverse effects to movement speed, save for attacking. This could mean that the planet they hailed from/the ship they were on had stronger gravity which they were used to, allowing them to lift weights on Cradle with ease. Kind of like Dragonball Z where Goku trains under extreme gravity and becomes ultra strong.

Have you ever playd "Loom"? In case you haven't read this
Doesn't he remind you of anyone. Nothing is visible but the eyes.
In the game the main charachter says:
" If you fear nothing, then you'd better not touch me"
What I think is that knights have nothing under their helms. They still is organic, he for example sleep, feel etc, but looking under his hood causes instant death.

The Jelly theory seems pretty good except for these three points.
-Jellies resist sleep. Knights don't.
-Knights use rock salt as an ingredient to cooking. Jellies can't touch it.
-About fiends being hated by every knight and Jellies hating fiends because of their shadow damage, keep in mind that Jellies deal piercing, which is the bane of fiends. Also Fiends dodge a lot. Jellies attacks are hard to dodge.

The energy was there to support the armor's life sustain systems...

http://wiki.spiralknights.com/Solid_Cobalt_Helm

Energy was stored in our suits and in the previous revive system, putting too much energy into the suits would cause an explosion or discharge from the suit.

Energy for elevators had nothing to do with out own selves, refrigerators need energy to run...

'sentient robots' do not need to eat, as the definition of robot is a humanoid computer, and computers use programs to run. the only thing they need is a source of electricity. yes computers do "sleep" however they are still running, same as organic creatures, however so far there isn't a way for a computer to turn itself back on while sleeping.

Previously stated in the thread we apparently switch parts... you mean we change armor, like people change clothes... I'm pretty sure just cause i can wear a different T-shirt I'm not a robot.

;^; but but... Jawas <3 DIS ART, i shall make it nao.